The present invention relates to an automatic document feeder having an ion generating function, and an image forming apparatus provided with the same.
It is no exaggeration to say that image forming apparatuses, such as a copier and a printer, are indispensable for offices and the like. Actually, offices are mostly installed with image forming apparatuses. Further, such image forming apparatuses have recently become familiar to us because they are spreading even to standard homes, hospitals and the like.
Among known image forming apparatuses, there are apparatuses of the type configured to supply the image forming section and fixing section thereof with air taken into the housing from around the image forming apparatus and then exhaust the air out of the image forming apparatus. One such image forming apparatus is provided with an air cleaning section configured to prevent harmful substances produced within the apparatus from being discharged out of the apparatus by eliminating harmful substances contained in a flow of air to be exhausted out of the apparatus to clean the air and then supplying negative ions to the air (see Japanese Patent Laid-Open publication No. 2005-4144 for example).
According to the technique described in Japanese Patent Laid-Open publication No. 2005-4144 noted above, it is necessary to eliminate toner particles, dust, ozone and the like produced by the image forming operation of the image forming section and, hence, an ion generating section having electrodes has to be unavoidably disposed at a location adjacent the image forming section and inside the air flow generated around the image forming section. As a result, a problem sometimes occurs that the ion generating efficiency of the ion generating section lowers earlier than expected due to the effect of silicon and the like produced around the image forming apparatus. Therefore, the above-described technique has a problem that the ability to clean air around the image forming apparatus lowers as the duration of use of the image forming apparatus becomes longer.
In cases where a unit having the air cleaning function is positioned outside the image forming apparatus in order to provide a larger distance between the ion generating section and the image forming section, an additional space is necessary for installation of such a unit, which results in a problem that an enlarged space is needed for installation of the image forming apparatus.
A feature of the present invention is to provide an automatic document feeder and an image forming apparatus which are capable of performing the function of generating ions stably over a long time period without upsizing of the device and the apparatus.